Process of carbonizing and distilling carbonaceous materials such as lignite, coal, wood, peat, and similar materials



Feb. 18, 1930.

w. w. ODELL 31 AS LIGNITE, COAL, WOOD, PEAT, AND SIMILAR MATERIALSOriginal Filed Nov. 29. 1922 2 Sheets-Sheet l PROCESS OF CARBONIZING ANDDISTILLING CARBONACEOUS MATERIALS SUCH b vE vToR @M Feb. 18, 1930. w. w.ODELL 7 1,747,731

PROCESS OF CARBONIZING AND DISTILLING CARBONACEOUS MATERIALS SUCH ASLIGNITE, COAL, WOOD, PEAT, AND SIMILAR MATERIALS Original Filed Nov. 29.1922 2 Sheets-Sheet 2 4 1104 Rwan- Mfflesses 5% @4 6 Patented Feb. is,1930' um'repf STATES PAT-ENT- OFFICE WILLIAM ODELL, OF PITTSBUNGH,PENNSYLVANIA, ASSIGNOR 'IO GLENN W.

- TRAEB, JR, MINNEAPOLIS, MINNESOTA- PROCESS OI CABBONIZING- ANDDISTILLING OABBONAGEOUS MATERIALS SUCH A8 LIGNITE; COAL, WOOD, BEAT, ANDSIMILAR MATERIALS Application filed November 29, 1822, Serial No.604,119. Renewed July 24, 1925.

This invention relates to the method of carbonizing or distillingmaterials by a continuous process wherein the materials are caused topass through a hot zone-fire zone-- in an opposite direction to the pathof the gaseous products of combustion, which latter pass directlythrough the materials in process.

The objects of this invention are:

1. To render the carbonizing process cheaper,

2. To increase the capacity for a given size installation,

3. To render the process simple of operation,

4. To afiord an easy means of discharging the carbonized product,

5. To afford a cheapmeans of cooling and quenching the carbonizedproduct,

6. To provide a means of burning some of the gas liberated, in contactwith the material in process, so as to economize fuel and hasten thecarbonization,

7. To provide a means for transferring 25. heat from the hottestparticles from carbonization to those less hot, after passing throughthe hot 'zones,

8. To provide a means for recovering some of the gas resulting from andduring process- 9. To provide a means for maintaining the mass ofmaterial in a loose rather than compact condition during processing andfor promotin a mixing of the particles, i 10. %0 process raw greenlignite and the like in one step Without previous drying.

In carbonizing coal, lignite, and the like,

it has been the practice to burn gas in heat-.

gases of combustion in the opposite direction through the material,passing same out through the incoming cooler material. The

hot zone is limited to a definite area, and the material is caused topass through it so quickt ly that only a very small percentage of thexed carbon is consumed in processing.

In the drawings:

Figure 1 is a front vertical sectional :view showing one form of thecarbonizer, in which internal fuel battles are formedintegral with thetuyeres which supply the air blast;

Figure 2 is a side elevation of the same typeof carbonizer;

Figure 3 is a side vertical sectional view of the same;

Figure 4 is a view partly in front vertical section and partly in frontelevation showing a modified form of carbonizer having separate airducts for supplying air from without the fuel mass, and Figure 5 is aside elevation of the upper portion of the carbonizer, shown in Figure4. In Figure 1, A is the oven wall, B is the mass of material inprocess, C and D are the upper and lower tuyeres, E is a gas ofitake andbattle, F is a zig-zag discharge from the oven proper, (Jr shows theinlets for steam or water for quenching, H is the revolving paddlemechanism by means of which the carbonized material is removed from theoven, I is the openin in the wall above base plate J, so adjusted t atby the natural angle of repose of the material treated the latterautomatically feeds onto H. K is a foundation and L the I-beam supportsfor the oven proper.

At M and N are shown a narrowing in the oven, at and just above the hotzone; 0 and P are the zones of slow travel of the carbonizing materials.Q, is the upper level or surface of the fuel in the oven, and R is thecooler for carbonized material, in which the zig zag discharge isretained.

In Figures 4 and 5 is shown another apparatus in which I havebeen ableto suecessfully carbonize materials by means of the same principles andprocess; the chief difference being that here air is admitted fromopenings in the outer wall instead of from no the dle and from withinthe fuel mass. The le tering in capitals refers to the same features inall of the figures. In these figures a and b are baflles controlling thecourse of the fuel downwards, c and d are the upper and lower sets ofair channels feeding air to the fuel through ducts e and f.

In Figure 5 is shown a portion of the oven proper in side elevation, andportrays the means of supplying air to the material in process. Theports e and f are shown open; these are plugged on the outside toprevent escape of an when the oven is in operation.

In operating according to my process and using the apparatus shown inFigure 1, I proceed as follows:

Fill the carbonizer (oven) with crushed or small sized fuel up to thefirst tuyere, start a fire at this level by igniting some wood or othercombustible, and add more fuel and start the air blast through the lowertuyere. Now add more fuel and repeat the ignition process at the uppertuyere, admitting air through the latter, and build the fuel up to thedesired level. Now start the discharge paddle drum H and replenish thefuel at frequent intervals by charging it into the open top of the ovenso as to maintain a fairly uniform fuel level. The fuel passes downthrough the hot zone and is carbonized, and the gases evolved during theprocess pass up through the fuel bed B and are in part burned within thefuel bed the remainder is burned at the fuel surface The air blastthrough the tuyeres is maintained throughout the operation. I find thatwith a given quantity of air blast through the tuyeres G and D, thedegree of carbonization is controlled by the velocity of travel of thefuel (the quantity of material put through the process per unit oftime)and that for a given rate of fuel input, the degree of carbonization is dependent on the uanity of air injected at C and D. Thecar onization is more complete as the rate of travel of the fuel isdecreased and as the quantity of air injected at Gand D is increased,and vice versa. At no time is the fuel discharged faster than the stateof ignition can be maintained at the tuyeres.

When-lignite-is passed through the apparatus, the resulting residue willbe a partly dried or thoroughly dry (water free) 7 llgnite, or acarbonized product containing volatile matter ranging from that of thethoroughly dried lignite to almost zero, accordingl as the rate ofdischarge is fast or slow. artly dried peat blocks have beensuccessfully carbonized in this manner, and likewise woodand. mixedfuels have been successfully treated thus.

Attempts have been made to utilize the producer gas generatingprinciples in carbonizing materials, by passing the fuel rapidlythroughthe producer, and such attempts have not been successful, because theper centage of fuel consumed was high and the carbonization uneven. Ihave found by experiment with large size apparatus that in order tocarbonize with a small consumption of fixed carbon, utilizing largelythe gas evolved to generate the heat required, it is necessary that thefuel must pass through the hot zone where air is admitted, very rapidly.This I believe is to be new, and is a feature of my process and of theoven which prov1des the means. When the fuel moves (preferably one abovethe other as shown in Figures 1, 3 and 4), with a slower rate of travelbetween these zones wherein the particles in process change positionwith respect to each other, the hotter giving up heat to the cooler,produces a more uniform product, and results in a decrease in thepercentage of fixed carbon consumed. This I believe to be a new featurein carbonizing processes.

Since gas will burn preferentially to car-- bon when air is admitted inthe presence of both at the temperature prevailing, I am I have foundfurther that enabled to burn considerable of this gas in a the uppercombustion zones (gas which is chiefly liberated below). A further advamtage gained by a rapid travel of the-fuel through the hot zones is thatthe reaction CO +C =2CO, which takes place rapidly only at hightemperatures, does not take place to the sameextent that it otherwisevwould, thus again reducing the fixed carbon consunfiption.

ow since it is difficult to heat a mass of fuel of any appreciablethickness by air blasting-that uel nearest the air supply alwaysbecoming intensely heated first-I have found it necessary to carbonizeby supplying the heat to thin layers at a time, and accordmgly have usedthis as a means of producing a high velocity of travel of the fuel inthe hot Zones; thatis, by placing the tuyeres in the narrow portions ofthe oven. This combinat1on I believe to be new andnovel.

In the oven as shown in Figure 1, the

'tuyeres C and D are so placed that they act as baffles which permit ofa certain amount of mixing of the particles after they pass and inpassing the tuyeres. A means is thus provided for the hottest particlesto comingle with the cooler ones and give up some of theirsensible heatto the latter; the fuel mass is considerably larger at these locations,0 and.

P, and the rate of linear travel is slower, thus allowing sufiicienttime for heat transfer and completion of carbonization. Considerable gasis evolved during this heat transfer in the widened portions of the oven0 and P (below tuyeres), and since it cannot escape elsewhere, it isforced upwards and reaches a maximum velocity in the restricted portionsof the oven, M and N, adjacent the tuyeres, more particularly the upperone, M. Now this is a particularly desirable feature, since it isdecidedly preferable to burn gas rather than burn carbon, and to usemore air through the upper tuyere. There is an excess of gas producedwhen carbonizing some materials such as lignite, peat, coal, etc. and Iprefer to burn some of this at the surface of the fuel bed, as at Q,Figure 1, for it is an aid in carbonizing. I have provided a means forwithdrawing some of the gas through the pipe shown at E, Figure 1. Thispipe has holes in its under side and conducts saidg'as from below thelower tuyere out of the oven. The

heating value of the gas at this level when carbonizing lignite or coalis 180 to 240 B. t. u. If a large amount of gas is removed,

. producer gas is generated and the heating value of the total gasremoved will depend on how much producer gas is made. The producer gasso made has a heating value of 140 B. t. u. per cubic foot. When justsufficient gas is withdrawn to operate the machinery for supplying theoven with air and power, its heating value is approximately 200 B. t.11. per cubic foot. With peat it is I slightly higher than this.

I have'found that the quantity of steam or water required for quenchingthe carbonized product is very much less than the calculated amount,indicating carbonization by heat transfer between particles in the ovenat O and P. Now this heat, transfer process aids materially in thecooling and quenching of the finished product, which is completelycooled by admitting exhaust steam through the pipes G, Figure 1. -Watermay be used in place of steam, but steam is preferable since a slightexcess of water impedes the flow of residue and alters the angle ofrepose of the material between I and H of Figure 1. The residue(carbonized product) iscooled, it will be noted, in a mixed atmos hereof gas and steam in which there is no ree oxygen; this apparently is abig advantage, for the product discharged, even though warm, does nottake fire spontaneously in the air, which is not the case when some ofsaid carbonized materials are quenched with water in the air.

The operation of this oven is automatic when fuel is supplied and theresidue removed, and hence the labor cost for operating is low. Thereare no complicated flue settings or other complications in the design ofthe oven which require specialists for the latters construction. Thisoven is get-at-able, and can be readily repaired when occasion re-'quires it. The first cost obviously is relative- I 1y low. It can bestarted and shut down frequentlv without damage, which is not true ofovens with complicated flue settings. I have completely carbonized asmuch as 20 tons of lignite per 24 hours in this oven (inside ovendimensions being: 6 feet long and 3 feet wide in the widest portion),the lignite charged contained 30 per cent moisture and was qrushedtosizes less than 2 inches in diameter. The air pressure used to obtainthis capacity was less than two inches of water by a water manometer;The carbonized product, amounting to slightly more than 40 per cent ofthe original lignite was suitable for briquetting, or for burning assuch.

The means of discharge, which I believe to be new, consists of arotating drum with radial blades as shown in Figures 1, 2, and 4 at H,upon which the cooled carbonized product flows, through an opening I inthe cooler, because of its tendency to assume a rather definite angle ofrepose. The quantity removed per unit of time depending on the speed ofthe rotating drum. Advantages claimed are that the discharge mechanismis always in sight, does not become overheated, can be repaired readily,and its operation is visible.

The operation of the oven shown in Figures 4 and 5 is the same. Here aand b are baflies, but are not also tuyeres, as are the baffies inFigure 1 (C and D).

The pipe E' shown'i'n all the fi ures is not only a gas ofi'take, but italso ta es some of the weight off of the zigzag part of the cooler, andthus leaves the residue therein in a looser state, and thus avoidsjamming.

I do not limitmyself to the use of air for promoting combustion in thisprocess, for

high temperature combustion gases with somea1r is just as satisfactory.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent, is:

1. A process for carbonizing and distilling solid carbonaceous materialin an oven, which consists in introducing the material to be treated,raising its temperature sufficiently to undergo combustion when treatedwith oxygen-carrying gas, passing the material substantiallycontinuously in a downward direction and alternately causing contractionand expansion of the same, dividing the charge into streams during thecontraction, causing the divided streams to then be brought together andallowed to expand, and

maintaining a high temperature during con-v striction and division ofthe charge.

2. A process for carbonizing and distilling solid carbonaceous materialin an oven, which consists in introducing the material to be treated,raising its temperature sufficiently to undergo combustion when treatedwith oxygen-carrying as, passing the material downwardly, and aternately causing it to expand andcontract, dividing the material intostreams at points of contraction, to increase the velocity at suchpoints, injecting an oxygen-carrying gas to maintain the material at ahigher temperature when traveling at this higher veloclty, causing apart of the gas evolved to pass through the material in an upwarddirection and tobe burned at the up per surface of the material, andmaintaining the material in a loose state.

3. A process for carbonizing and distilling solid carbonaceous materialin an oven, which consists in introducing the material to be treated,raising its temperature sufficiently to undergo combustion when treatedwith oxygen-carrying gas, in causing a charge of material to movecontinuously downwardly, then constricting and dividing the charge tosubstantially increase its rate of flow, then causing said charge toexpand to reduce its velocity, and introducing air during constrictionand division.

4. A process for carbonizing and distilling solid carbonaceous materialin an oven which consists in introducing the material to be treated,raising its temperature sufiiciently to undergo combustion when treatedwith an oxygen-carrying gas, causing the materialto move throughsuccessive alternate combustion and heat-equalizing zones, passing thematerial in relatively restricted streams and at relative high velocitythrough said combustion zones, causing the streams to unite.

and travel in a single stream and at a relatively lower velocity throughthe heat-equalizing zones, introducing an oxygen-carrying gas into thematerial at the combustion zones.

5. In a process as defined in claim 4, the step which consists inpassing the materials undergoing carbonization through the combustionzones at a velocity too great for their complete combustion but slowenough to maintain partial combustion sufficient to raise thetemperature of said combustion zones substantially above the temperatureof the heatequalizing zones.

6. In a process as defined in claim 4, the step consisting in passingthe gaseous products resulting from partial combustion of the materialsundergoing a carbonization in a direction substantially counter to theflow of said materials.

through the carbonaceous materials in an consists in introducing thematerial to be treated, raising its temperature sufliciently to undergocombustion when treated with an oxygen-carrying gas, causing thematerial to move through successive alternate combustion andheat-equalizing zones, in such manner that the gases evolved in a lowercombustion zone will pass to an upper combustion zone, and supplying anoxygen-carrying gas to the upper combustion zone'so as to cause theburning of said gases thereat with a material reduction in theconsumption of the fixed carbon of the material, and withdrawing thesolid carbonized combustible residue. 10. A process for carbonizing anddistillmg solid carbonaceous material in an oven which consists inintroducing the material to be treated, raising its temperaturesufficiently to undergo combustion when treated with an oxygen-carryinggas, causing the material to move through a series of hot zones in whichactive combustion is maintained by supply- 1ng oxygen-carrying gasseparately to each of said zones, conducting said material through saidzones in substantially parallel and relatively restricted streams and ata velocity too great for its complete combustion, and then withdrawingthe solid carbonized combustible residue.

11. A process for carbonizing and distilling solid carbonaceous materialin an oven which consists in introducing the material to be treated,raising its temperature sufliciently to undergo combustion when treatedwith an oxyge -carrying gas, causing the material to move throughalternate combustion and heatequalizing zones, maintaining combustion insaid combustion zones by supplying thereto an oxygen-carrying gasconductlng said material through the combustion zones in substantiallyparallel streams and at a velocity too great for its completecombustion, and through the heat-equalizing zone in substantially asingle conjoint stream at less velocity, and withdrawing the solidcarbonized come bustible residue. 12. A process for carbonizing anddistilling solid carbonaceous material in an oven .which consists inintroducing the material to be treated, raising its temperaturesufiiciently to undergo combustion when treated with an oxygen-carryinggas, causing the material to' move through successive hot zones inrestricted streams, and at a relatively high velocity maintainingcombustion at each hot zone by introducing an oxygen-carrier thereat,caus ing the gaseous combustion products to pass substantially counterto the path of the mateoxygen-carrying gas, causing the material to movein a loosestate, to pass downwardly through a series of hot zones inrestricted streams, maintaining combustion at each zone, causing thegases evolved by combustion to pass through the material in a generallyupward direction, causing the material to remain in a loose state andcommingling the articles, and withdrawing the solid carbomzedcombustible residue.

14:. A process for carbonizing and distilling solid carbonaceousmaterial in an oven which consists in introducing the material to betreated, raising its temperature sufliciently to undergo combustion whentreated with an oxygen-carrying gas,- causlng the material to movecontinuously in a downward direction and alternately contracting andexpanding the same causing the material to be divided into streamsduring contraction to obtain a relatively higher velocity, maintainingthe material at relatively high temperature during division, and thencombining the streams after contraction in a manner to reduce thevelocity and obtain a reduction in temperature.

15. A process for carbonizing and distilling solid carbonaceous materialin an oven which consists in introducing the material to be treated,raising its temperature sufficiently to undergo combustion when treatedwith an oxygen-carrying gas, causing the material to move continuouslyin a downward direction, causing the material to-be contracted, thendividing the material while thus contracted into separate streams toobtain a relatively higher velocity, causing combustion to take place'during said higher velocity, and then causing the streams to combineinto a single stream, to travel at a relatively lower velocity, andmaintaining a higher temperature during division, by introduction of anoxygen-carryihg gas.

16. A process ing solid carbonaceous material in an oven, which consistsin filling the oven with said material in stages and igniting thematerial at each stage, causing the material to move substantiallycontinuously through the oven, alternately contractingand expanding thematerial during motion and causing it to move at relatively highvelocity during contraction, applying an oxygen-carrying gas during suchcontraction and high velocityfor carbonizing and distill motion, andwithdrawing the solid carbon ized combustlble residue through the oven.

. 17. A process for carbonizin and distilling solid carbonaceousmateriain an oven,

which consists in fillin the oven with said material in stages andigniting'the material at each stage, causing the material to movesubstantially continuously through the oven, alternately contracting andexpanding the material during motion and causing it to move atrelatively high velocity during contraction, applying an oxygen-carryingas dur ng such contraction and high ve ocity motion, partly effectingthe heating of the material to combustion temperature by upward passageof the heated gases of combustion, and utilizing the withdrawing actionof the combustible residue as a means to control thefeed of the materialthrough the oven.

18. A process for carbonizing and distillfing solid carbonaceousmaterial in an oven,

which consists in filling the oven with said material in stages andigniting the material at each stage, causing the material to movesubstantially continuously through the oven, alternately horizontallycontracting and expanding the material during motion and causing it tomove at relatively high velocity during contraction, applying anoxygen-carrying gas during'such contraction and high velocity motion,and withdrawing the solid carbonized combustible residue through theoven.

19. A process for carbonizing and distilling solid carbonaceous materialin an oven, which consists in filling the oven with said material instages, igniting the material, causing motion of the material,alternately contracting and expanding the material during motion throughthe oven, and causing ity to move at relatively high velocity and inthinner layers during contraction, applying an oxygen-carrying gasduring such contraction and high velocity motion, and withdrawing solidcarbonized combustible residue.

20. Aprocess for carbonizing and distill ing solid carbonaceousmaterialin an oven, which consists in filling the oven with saidmaterial in stages and igniting the material ly during contraction,introducing oxygencarrying gas during contraction and more rapid'motion,and controlling downward motion by removal of the solid carbonizedcombustible residue.

21. A process for carbonizing and distilling soiled carbonaceousmaterial in an oven, which consists in partly filling the oven with thematerial to be processed, raising the temperature of the materialsufiiciently to undergo combustion when directly treated with anoxygen-containing gas, causing the material to travel through the ovenin relatively restricted streams at relatively high velocity, applyingthe oxygen-containing gas during such streaming and velocity, causingthe streams to unite and move at a relatively lower velocity,withdrawing the solid carbonized combustible residue, and utilizing thewithdrawing action as a means to control the downward feed of thematerial.

WM. W. ODELL

